1. Technical Field
This invention relates generally to subscriber services for telecommunications devices. More particularly, the invention relates to a method and apparatus to call back a momentarily unavailable user of a telecommunications device in an automated fashion.
2. History of Related Art
A number of subscriber services are available to users of telecommunications devices, such as mobile cellular telephones, including ring-back or call-back services. Essentially, when a calling party attempts to call another party already engaged in conversation, these services allow the calling party to activate a call-back service whereby the called party is dialed upon termination of the pre-existing conversation. Such services are also known by the popular names of xe2x80x9cCall Busterxe2x80x9d or xe2x80x9cBusy Buster.xe2x80x9d In any case, these services are quite convenient. They serve to relieve the calling party of continually dialing the number of the called party until after a busy signal is no longer received, and the calling party is free to complete the connection with the called party.
Currently available call-back services do not, however, account for the situation where the called party is not reachable, such as when not located in the local service area when the party is engaged in a call, or when the called party has turned off its phone. In these cases, the call-back service fails.
Thus, what is needed is a method and apparatus for implementing a call-back service by a subscriber attempting to call a telecommunications device operated by a called party when the called party is unavailable due to turning off the telecommunications device, engaging in a call, or roaming out of the service area so that the received and/or transmitted signals are too weak to be picked up by the local base station. Such a method and apparatus would be even more useful if it provided an announcement to the calling party when the called party subsequently became available, and offered the option of calling back the called party at that time, as previously ordered by the calling party.
The invention includes a method of implementing a call-back service by a calling party attempting to call a telecommunications device operated by a called party, comprising the steps of placing a call to the telecommunications device, receiving an indication that the device is not available (e.g., meant to include xe2x80x9cnot locatedxe2x80x9d, or xe2x80x9cnot foundxe2x80x9d, or xe2x80x9cbusyxe2x80x9d), and ordering a subsequent call to be placed to the device upon subsequent registration (i.e., when the device becomes available). In other words, if the device does not respond to a LOCATIONREQUEST message from the appropriate Home Location Register (HLR), then the method of the present invention may be fully employed.
The method may include the steps of receiving an indication that the device is available, and placing a subsequent call to the device. Further, the method may include the steps of notifying the calling party that the device is available, and querying the calling party as to whether the subsequent call should be placed.
Typically, the telecommunications device is associated with an A-number, and the original (non-completed) call is placed to the device by dialing the A-number. A subsequent call to the device may also be placed by dialing the A-number. Alternatively, the subsequent call may be made by simply entering a preselected feature code by the calling party, with the A-number being automatically dialed. An announcement that the device is turned off, busy, or out of range may constitute receiving an indication that the device is not available. Ordering a subsequent call to be placed to the device upon registration may include the step of entering a preselected feature code.
In an alternative embodiment, the method of the present invention may be employed in a situation where a second HLR, having a table with an HLR reference field, is associated with the telecommunications device. This reference field typically points to a first HLR associated with the subscriber. Thus, inter-HLR operations can be accommodated by the method of the present invention. To make use of the first and second HLRs, the method in this case includes the steps of notifying the first HLR that the device is registered, and notifying the subscriber that the device is available.
The invention also includes a node or network adapted to implement a call-back service by a calling party attempting to call a telecommunications device operated by a called party, comprising a node for placing a call to the telecommunications device, receiving an indication that the device is not available, and receiving an order to place a subsequent call (the xe2x80x9ccall-backxe2x80x9d) to the device upon registration.